Erwin with his psi can do
Calculations quite a few.
But one thing has not been seen:
Just what does psi really mean?

As translated by Felix Bloch, and quoted in Traditions et tendances nouvelles des études romanes au Danemark (1988) by Ebbe Spang-Hanssen and Michael Herslund, p. 207; also in The Pioneers of NMR and Magnetic Resonance in Medicine : The Story of MRI‎ (1996) by James Mattson and Merrill Simon, p. 278